Unicast IP (Internet Protocol) content delivery is preferred in many cases for content delivery to IP capable devices such as computers, tablets and/or other devices coupled to a home network. This is because unicast IP supports acknowledgements allowing the IP devices to signal the failure to properly receive a packet and also allows the transmitting device to send a content stream, e.g., a video content stream, which has been encoded in a manner that is particularly well suited for the receiving device and at a rate which can be supported.
For example, the same content but encoded using different coding schemes may be sent to IP devices with differing capabilities. The content may be transmitted at a high data rate to a first device with a powerful processor being able to receive, process and decode the high data rate version of the content. At the same time a low data rate version may be sent to another device, e.g., a handheld device with a small display, limited processing power and a low data rate connection, e.g., a WiFi connection to a cable modem where the WiFi connection has limited or poor signal quality and thus constrained bandwidth capability.
In order to support a wide range of data rates and devices, the content provider may code the same content multiple times using different encoding schemes and for different data rates. The coder used to code the content supplied from the network headend or another content server maybe a relatively powerful and expensive device which does high quality encoding. This is commercially possible given that the content coded for delivery from the network headend or content server is likely to be provided to numerous devices with the cost of the coder being a cost that is effectively shared over multiple devices.
While unicast IP content delivery is desirable for many reasons, it has the potential to place a large burden on the delivery network extending from the content server or network headend from which the content is streamed to various household which may share one or more links to the content server providing the content. This is particularly common where a cable network is used to stream content to one or more households but also occurs in the case of delivery via a fiber network.
As networks move towards increased unicast IP content delivery the potential loading on the networks links between a content server and one or more households is likely to increase. While demand for unicast IP content delivery is likely to increase, the demand for content delivery via Switched Digital Video, analog broadcasts and/or other non-unicast delivery methods is likely to decrease over time as more and more devices switch to unicast content delivery with the content normally being expected to be supplied via a server.
Thus, over time, the demand on a cable network's non-unicast content delivery capability is likely to decrease as the demand for unicast IP content delivery increases.
In many households, gateway devices capable of receiving content via conventional cable services such as Switched Digital Video, Video on Demand, Analog broadcast and/or types of content channels used to deliver the same content stream to multiple households are being deployed. Such gateway devices normally support recording, transcoding and/or transrating capabilities and can receive content via a cable network channel and generate an IP unicast stream therefrom which can be delivered over a home network or another network coupled to the gateway device.
While gateway devices often support transcoding and/or transrating capability, the quality of the coders in home gateway devices is often relatively poor compared to those used to encode content placed on content servers which will supply content to numerous households. In addition, while a content server may support a large number of different encoding formats and data rates allowing the best match with a particular end device's capabilities, home gateway devices often support fewer encoding schemes and/or data rates. As a result of a home gateway's limited ability to encode and support a wide variety of encoding schemes, the quality of video received from a home gateway often appears inferior to that streamed from a content server that serves multiple households.
While some content may be broadcast over a cable network according to a transmission schedule, in many cases content being supplied via unicast IP streams may not be delivered via a broadcast or other non-IP unicast content delivery method at the time it is being supplied via unicast IP to one or more devices.
As the number of devices requesting content via unicast IP content delivery streams increases the chance that congestion will occur on a shared link also increases. At the same time the probability that multiple devices in a household, region, or service group supplied via a common network link will be requesting the same content at a particular point in time also increases. This is particularly the case where a hometown or regional sporting event may be the cause of the high demand on a particular link.
In view of the above discussion, it should be appreciated that there is a need for developing methods and/or apparatus which would help in alleviating congestion over the service provider's delivery network by reducing and/or avoiding the number of devices to which unicast content streams need to be delivered via a shared or common network link. As noted above, cable and fiber network are particularly likely to encounter such a congestion situation since a shared link may service many households.